ORIGINAL DATA:

The dataset: "33_50_DATA.csv" is the original dataset, downloaded from the replication package of "Rong Zhou, Xiang Bi, and Kathleen Segerson. Evaluating voluntary environmental programs with spillover effects. Journal of the Association of Environmental and Resource Economists,7(1):145–180, 2020".

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BASELINE ANALYSIS CODES:

The first stage codes that estimate the thresholds: "Threshold_Estimate_subgroups" and "Treshold_Estimate_all". They are R codes.

Codes that prepare the second stage analysis data according to the first stage results: "Baseline_Prepare_for_Second_Stage_1991", "Baseline_Prepare_for_Second_Stage_1992", "Baseline_Prepare_for_Secon_Stage_1993_1995", "Baseline_Prepare_for_Second_Stage_all_years". They are R codes. These data are in the folder "Prepared_Data"

The second stage codes that estimate the heterogeneous participation effects: "Second_Stage_1991", "Second_Stage_1992", "Second_Stage_1993_1995", "Second_Stage_All", "Second_Stage_No_Outliers". They are Stata codes.

Main results in the paper: 
"Treshold_Estimate_1991" and "Treshold_Estimate_all_years" produce  Figure 4 and Table 4;
"Baseline_Prepare_for_Second_Stage_1991", "Baseline_Prepare_for_Second_Stage_all_years", and "Second_Stage_No_Outliers" produce Table 5.

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TECHNOLOGY SPILLOVER ANALYSIS CODES: 
The following codes and data files are all in the subfolder "Technology Spillover"

Prepared data from Zhou et al. 2020: The original file is "addYearSpecificSpillover4.dta", downloaded from the replication package. This data is directly used for the second stage analysis for all years participants. "data_spillover_all.csv" is the .csv version of the exact same dataset.

Code that prepares the second stage analysis data for 1991 participants: "Prepare_Secound_Stage_1991". This is a R code.

The second stage codes: "Second_Stage_1991" and "Second_Stage_1991_1995". They are Stata codes. They produce Table 6.




